Spillover Effects of Adult Medicaid Expansions on Children's Use of Preventive Services.

BACKGROUND: Since the passage of the Affordable Care Act, Medicaid enrollment has increased by ∼17 million adults, including many low-income parents. One potentially important, but little studied, consequence of expanding health insurance for parents is its effect on children's receipt of preventive services.
METHODS: By using state Medicaid eligibility thresholds linked to the 2001-2013 Medical Expenditure Panel Surveys, we assessed the relationship between changes in adult Medicaid eligibility and children's likelihood of receiving annual well-child visits (WCVs). In instrumental variable analyses, we used these changes in Medicaid eligibility to estimate the relationship between parental enrollment in Medicaid and children's receipt of WCVs.
RESULTS: Our analytic sample consisted of 50 622 parent-child dyads in families with incomes <200% of the federal poverty level, surveyed from 2001 to 2013. On average, a 10-point increase in a state's parental Medicaid eligibility (measured relative to the federal poverty level) was associated with a 0.27 percentage point higher probability that a child received an annual WCV (95% confidence interval: 0.058 to 0.48 percentage points, P = .012). Instrumental variable analyses revealed that parental enrollment in Medicaid was associated with a 29 percentage point higher probability that their child received an annual WCV (95% confidence interval: 11 to 47 percentage points, P = .002).
CONCLUSIONS: In our study, we demonstrate that Medicaid expansions targeted at low-income adults are associated with increased receipt of recommended pediatric preventive care for their children. This finding reveals an important spillover effect of parental insurance coverage that should be considered in future policy decisions surrounding adult Medicaid eligibility.